Andrew Reilly, Presenter: Nothing to Disclose

David Ian Thwaites, Abstract Co-Author: Nothing to Disclose

Although methods for the objective assessment of image quality are well established, in practise these tend to vary between modalities and few centres employ them for routine QA. The IQ Works software package implements a consistent cross-modality framework for the automated, objective and quantitative analysis of image quality.

Image quality phantoms tend to consist of the same test components in different geometrical configurations, regardless of the specific modality. An extensible framework has been developed comprising analysis modules for each component. ‘Analysis trees’ for particular phantoms are constructed, stored in a phantom library then recalled for automatic processing of test images. Analysis modules include geometrical alignment and linearity, response curve, uniformity, MTF, NPS and DQE. Each module is verified against independent methods on standard test images. Reports are generated and results stored in a database to facilitate trend and statistical analyses. The user is alerted if individual results do not lie within defined tolerances. Trees have been developed for CT, DR, CR, MRI, DRR and EPID phantoms.

IQ Works is used routinely for QA in Edinburgh. Although more comprehensive and robust, the new system is also more straightforward and efficient, reducing the time for routine testing to less than a fifth and enabling complex assessments to be performed by radiographers and technicians. All module results agree (<1%) with accepted methods. Detailed analyses have yielded valuable results, especially early indicators of deterioration requiring intervention.

IQ Works models commercial and bespoke phantoms and is an efficient and consistent cross-modality means of objective performance evaluation. Being automated, the package is invaluable during commissioning and complex assessments can be performed by any staff group. It has been launched as an open-source system by a consortium of IPEM, CTUG and others in the UK. Download address: http://www.iqworks.org.

Providing a uniform cross-modality framework for objective performance evaluation, IQ Works enables more widespread adoption of these methods for commissioning and routine QA.

Reilly, A, Thwaites, D, IQ Works: An Automated Image Analysis Framework for the Objective Assessment and Optimisation of Image Quality.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5009358.html